title: Population-based prospective study of the combined influence of cigarette smoking and Helicobacter pylori infection on gastric cancer incidence: the Hisayama Study.
abstract: The authors assessed the separate and joint influences of cigarette smoking and Helicobacter pylori infection on the development of gastric cancer in a population-based prospective study. A total of 1,071 Japanese men aged > or =40 years were followed up prospectively for 14 years (1998-2002). Compared with that for current nonsmokers, the multivariate-adjusted hazard ratios of gastric cancer for smokers of 1-9, 10-19, and > or =20 cigarettes per day were 1.36 (95% confidence interval (CI): 0.50, 3.71), 1.93 (95% CI: 1.01, 3.67), and 1.88 (95% CI: 1.02, 3.43), respectively. The risk of gastric cancer increased steeply for subjects who had both a smoking habit and H. pylori infection compared with those who did not have both risk factors (hazard ratio = 11.41, 95% CI: 1.54, 84.67). If causal, the estimated population attributable fraction of gastric cancer for cigarette smoking was approximately half that for H. pylori infection (28.4% vs. 56.2%). The overlap of the population attributable fractions for the 2 factors was 49.6%. Findings suggest that cigarette smoking and H. pylori infection are significant risk factors for gastric cancer in Japanese men, and the magnitude of their combined influence is considerable.
authors.affiliation: Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shikata
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Doi
authors.forename: Koji
authors.initials: K
authors.lastname: Yonemoto
authors.forename: Hisatomi
authors.initials: H
authors.lastname: Arima
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Ninomiya
authors.forename: Michiaki
authors.initials: M
authors.lastname: Kubo
authors.forename: Yumihiro
authors.initials: Y
authors.lastname: Tanizaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Iida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kiyohara
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011446:Prospective Studies; D012307:Risk Factors; D012424:Rural Population; D012907:Smoking / Q000009:adverse effects*; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000209:etiology